Residential and commercial air conditioners include as a part thereof a fan coil unit. The fan coil unit includes a coil through which coolant (liquid or gas) is pumped, and normally the coil is supported above a condensation pan or convector tray having one or more openings through which air is blown by one or more fans powered by motors which are supported below and from the condensation pan. The air passing through the coil creates condensation on the coil which drips down upon the condensation pan or primary pan, and is then conducted by an appropriate outlet and a discharge pipe to a secondary pan and therefrom to a drain.
Such conventional convector trays or primary pans are generally made from galvanized metal and rust with relative ease. Once the convector tray rusts the water might, for example, drip down into the underlying motor(s) which drives the fan(s), causing the motor to short-out. Excessive rust also blocks or reduces normal drainage which results in fungus growth which in turn can cause odors and also can cause the normal drain opening to close or appreciably block with, of course, attendant overflow and damage.
The latter-identified patent reduces rust and fungus growth associated with conventional galvanized metal primary pans. However, it has also been found that sponge rubber seals or rubber gaskets associated with such conventional primary pans and condensation coils also deteriorate and virtually break-down into "dust" or extremely small particles which block or reduce drainage of condensation from the pans. This same deteriorated rubber/particles also results in fungus growth which in turn can also cause the heretofore noted undesirable odors. Furthermore, when such rubber gaskets deteriorate and disintegrate, a gap is formed between the bottom of the condensation coil and the primary pan through which air which is normally forced through the condensation coil flows through this gap. Since the air which passes through the gap does not pass through the condensation coil, the efficiency of the overall unit is appreciably diminished. Furthermore, condensation which collects in the primary pan also attacks conventional metallic fasteners which secure the motor housing to the bottom of the primary pan with the result that the motors can actually tear loose from the pan. However, even if this does not occur, water can drip through the fastener openings in the primary pan as the fasteners and the periphery of the metal surrounding the openings corrodes, and such leakage can enter the electric motor resulting in the shorting and permanent damage thereof.